Proximity sensors or "curb sensors" for cars and other motorized vehicles have generally taken the form of an elongated, coiled sheet metal probe which is clamped to the inside of the fender and projects to the position the curb would assume alongside the vehicle when parking. The actual physical scraping sound of the probe on the curb indicates when the vehicle is sufficiently close to the curb for parallel parking, for example. Otherwise, it indicates at which point the car is in danger of having its whitewalls scratched up.
This system worked reasonably well in the 1950's, when air conditioning was all but unheard of in cars. However, as cars become increasingly luxurious and complex, with air conditioning and high quality stereo sound systems, the effectiveness of the physical scraping sound of a metal rod on the curb as an alert is virtually non-existent.
To remedy this, several curb sensors, or proximity sensors, which have internally actuable alarms, such as a light or a buzzer, have been invented. One was invented by the instant inventor and bears U.S. Pat. No. 4,390,862, and was issued June 28, 1983. Another sensor system developed by the instant inventor is described in U.S. Pat. No. 4,460,889, issued July 17, 1984.
These units work very well for the purpose for which they were intended, that is, they can be arranged individually or in duplicate or triplicate on a vehicle and will indicate when the probe has been deflected by means of an audible or visual signal on the dashboard.
There are, however, more sophisticated implementations of the above inventions which would provide the driver with even more information about his position vis-a-vis external objects, and which would be particularly apropos for use with large vehicles and recreational vehicles which may have overhead clearance problems, as well as front and rear curb clearance difficulty.